A review of carbon monitoring in wet carbon systems using remote sensing

Abstract

Carbon monitoring is critical for the reporting and verification of carbon stocks and change. Remote sensing is a tool increasingly used to estimate the spatial heterogeneity, extent and change of carbon stocks within and across various systems. We designate the use of the term wet carbon system to the interconnected wetlands, ocean, river and streams, lakes and ponds, and permafrost, which are carbon-dense and vital conduits for carbon throughout the terrestrial and aquatic sections of the carbon cycle. We reviewed wet carbon monitoring studies that utilize earth observation to improve our knowledge of data gaps, methods, and future research recommendations. To achieve this, we conducted a systematic review collecting 1,622 references and screening them with a combination of text matching and a panel of three experts. The search found 496 references, with an additional 78 references added by experts. Our study found considerable variability of the utilization of remote sensing and global wet carbon monitoring progress across the nine systems analyzed. The review highlighted that remote sensing is routinely used to globally map carbon in mangroves and oceans, whereas seagrass, terrestrial wetlands, tidal marshes, rivers, and permafrost would benefit from more accurate and comprehensive global maps of extent. We identified three critical gaps and twelve recommendations to continue progressing wet carbon systems and increase cross system scientific inquiry.

Addressing Tidal Flooding Induced uncertainties in Satellite Derived Global Salt Marsh Change Studies: Impact on Blue Carbon Monitoring

“…Therefore, it is of utmost importance that such studies focus significantly on uncertainties associated with satellite based estimates of wetland biophysical parameters. The authors have acknowledged the uncertainties associated with exclusively using remote sensing techniques for blue carbon monitoring in their previous studies 11 . In a 2020 study 12 similar to the current analysis, they specifically acknowledged the importance of tide filtering techniques such as Tidal Marsh Inundation Index (TMII) 4 in the accurate historical assessment of salt marshes.…”

Assessment of the NASA carbon monitoring system wet carbon stakeholder community: data needs, gaps, and opportunities

“…Although previous research has focused on the impacts of a changing environment on the biosphere (Keith et al 2021) and atmosphere (Xiao et al 2019), here we concentrate on the hydrosphere and carbon cycling systems that operate in wetlands, oceans, rivers, streams, lakes and ponds as well as in permafrost. Collectively known as wet carbon (WC) systems, they are critical to the carbon cycle (Campbell et al 2022). They are also essential to support humanity, including agriculture, hydroelectric power, groundwater systems, and a multitude of sanitary and drinking water systems.…”

“…A recent review of monitoring WC via remote sensing (Campbell et al 2022) examined 574 publications across nine WC systems: mangroves, tidal marshes and flats, mineral wetlands, peatlands, permafrost, lakes, rivers, oceans, and coastal and continental shelf seas. By including all freshwater, saline and brackish aquatic and wetland ecosystems, the review focused on a broad grouping of carbon-cycle systems with shared data needs, restoration and preservation priorities, and research directions.…”

“…They are involved in WC decision-making processes in the systems of interest, and can be private companies, nongovernmental organizations (NGOs), government agencies ranging in scope from local to federal, parastatals, international organizations, and more (Brown et al 2022). CMS stakeholders can also include cities and townships, international organizations, nongovernmental bodies, universities, and sub-national bodies (Campbell et al 2022). The objective of this paper is to identify and characterize stakeholders associated with WC systems, evaluate their interests and relationships with the system, and determine existing gaps between scientific knowledge and their information requirements.…”

“…Our primary objective was to gain valuable insights into the ways in which stakeholders involved in WC utilize information in their work, and to identify any existing unmet information requirements. Specifically, the focus of research was to assess whether the current datasets and the research presented in the academic review of Campbell et al (2022) are adequate to support the current decision-making processes and to gauge the knowledge and awareness of organizations about satellite-derived carbon datasets.…”